<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    /* 继承性：都是继承谁离得近 */
.box{
    color: aqua;
}   
#box{
    color: black;
}  
.ibox{
    color: brown;
    
}
.aa{color: teal;}
.dd{
    color: aqua;
}
.cc{
    color: brown;
}
.bb{
    color: yellow;
}

    </style>
</head>
<body>
    <div class="box" id="box">
        <span class="ibox
        "><span >123</span></span>
    </div>
    <div class="dd">
        <div class="cc">
            <div class="bb">
                <div class="aa">
                    <span>123</span>
                </div>
            </div>
        </div>
    </div>
    
</body>
</html>